Morphological Effects in Photonic Integrated Nanojet

We report a study of the shape-dependent optical response of a photonic nanojet created by a single Si
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microdisk illuminated by a waveguide. High intensity sub-wavelength spots and low divergence nanojets are observed at the telecommunication wavelengths. Light scattered from the disk is observed by imaging from above. The electromagnetic distributions inside and outside the microdisk are calculated by using finite-difference-time-domain method and compared to the experimental image. We demonstrate that small morphology variations can have a major impact on the optical properties of the entire system. These results deepen our understanding between the disk morphology and its optical response and provide insight toward potential applications in high-resolution optical imaging, biophotonics, and optical data storage.